<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      /* 定位:注意左右padding */
      div {
        position: relative;
        left: 0;
        top: 0;
      }
      header {
        position: absolute;
        left: 0;
        top: 0;
        width: 200px;
        height: 100vh;
        background-color: rgb(201, 159, 105);
      }
      aside {
        padding: 0 200px;       
        height: 100vh;
        background-color: blanchedalmond;
      }
      footer {
        position: absolute;
        right: 0;
        top: 0;
        width: 200px;
        height: 100vh;
        background-color: burlywood;
      }
    </style>
  </head>
  <body>
    <div>
      <header></header>
      <aside></aside>
      <footer></footer>
    </div>
  </body>
</html>
